The part doing the work: governor flyweights, jaw, lever, rods and wedgesCar on two T-rails; counterweight; traction machine with a spring-applied brakeA 1,000 kg, 1 m/s traction lift (numbers from a published worked example and EN 81-20). Cut power and the brake's springs shut it. Cut every hoist rope and the governor, turning with its own rope, trips at 1.3 m/s (EN window 1.15–1.5); its rope lifts both wedges 4 mm onto the rails and the car stops at 0.6 g (EN window 0.2–1 g), about 18 cm later. Event shown 20× slower. Bops Lab